Field
This disclosure is generally related to distribution of digital content. More specifically, this disclosure is related to a system for explicitly deleting content which is cached at intermediate routers in a CCN.
Related Art
The proliferation of the Internet and e-commerce continues to create a vast amount of digital content. Content-centric network (CCN) architectures have been designed to facilitate accessing and processing such digital content. A CCN includes entities, or nodes, such as network clients and consumers, forwarders (e.g., routers), and content producers, which communicate with each other by sending interest packets for various content items and receiving content object packets in return. CCN interests and content objects are identified by their unique names, which are typically hierarchically structured variable length identifiers (HSVLI). An HSVLI can include contiguous name components ordered from a most general level to a most specific level. As an interest is routed through the network from a consumer to a producer, each intermediate CCN router adds an entry in its pending interest table (PIT) corresponding to the interest and forwards the interest to the next CCN router. When a matching content object is generated by and sent from the producer back to the consumer, the content object follows the reverse path of the interest. Each intermediate CCN router can cache a copy of the content object, which allows the router to fulfill a subsequent interest for the content from its cache.
The lifetime for content cached in a router may depend upon the amount of space present in the cache, the cache eviction policy of the router, and the timeout specified by the producer. For example, under a router's eviction policy, a router may evict or remove content from its cache if there is insufficient space for new content, or if the content has surpassed its lifetime, such as a producer-specified timeout. However, the current CCN protocol does not provide for explicit deletion commands, e.g., a request to explicitly evict content from the cache.